This is a double-blind placebo-controlled trial contrasting the effects of a soy dietary supplement with thsoose of conjugate estrogens (HRT) on health and qual-ity of life measures in perimenopausal women randomized into 3 groups: soy, HRT and placebo. The study aims to determine the impact of the interventions on meno pausal complaints, plasma lipids, vaginal bleeding, endometrial proliferation, & to evaluate changes in health-related quality of life. This collaborative study also assesses the impact on carotid arteries, bone density and clinical outcome.